A short-range Radio Frequency (RF) transmitter comprises an RF signal-generation unit, a power amplifier, an impedance-matching network, a control unit and an antenna. The RF signal-generation unit generates an RF signal. The power amplifier amplifies the RF signal. The antenna radiates the amplified RF signal. The impedance-matching network matches the output impedance of the power amplifier to the input impedance of the antenna. The control unit controls the operations of the RF signal-generation unit and the power amplifier.
If one or more of the RF signal-generation unit, the power amplifier and the impedance-matching network has failed or malfunctioned, the power delivered to the antenna becomes very low. Consequently, the required RF power to ensure the radio link may not be radiated.
There already exists a system that solves this problem to some extent. The system detects faulty conditions, such as low transmitted power and high reflected power to rapidly switch off the power amplifier or turn on a backup transmitter. However, the system does not alert the control unit when the power amplifier or the RF signal-generation unit fails.